"I'd be much more impressed if he said, as a Muslim, he now recognizes the act of violence was wrong and in violation of the Koran," Reese said. "But if he still believes what he does is justified and good, then that's problematic.
"For political and diplomatic reasons, Britain may have other reasons for releasing him, but he doesn't fulfill the checklist," he said.
Peter Singer, the Ira W. DeCamp professor of bioethics at Princeton University, sees no association between the Vick case and those responsible for mass murder.
As for al-Megrahi, "He should be shown no compassion for the people he killed," Singer said. "He showed no remorse and I think you shouldn't give someone less than 20 years for murder. For a lot of people, it sends the wrong message."
Singer, whose publication of the 1975 book "Animal Liberation" began the animal rights movement, is gentler on Vick.
"He's certainly shown remorse for what he has done and is seeking to make amends," Singer said. "He served his full term. Should you penalize someone on top of what the judge sentenced and never play football again?
"He is helping against dog fighting and working with kids to see that dog fighting isn't a cool thing to do. I see him as actually trying in some way to compensate, making good for the wrong thing he did."
Vick might even be a good role model, as he is allowed to "rehabilitate," he said.
Singer cited an old friend, Donald Barnes, who spent 16 years as a researcher doing "horrible experiments" on monkeys, but later became director of education for the National Anti-Vivisection Society, which seeks to eliminate the use of animals in product testing.
"He eventually saw it was wrong and was a spokesperson for the opposition," Singer said. "Those in the movement forgave him and accepted him as a supporter. People can generally forgive, but you want to do it with deeds."
But many people queried by ABCNews.com, who asked not to be identified, have more venom in mind.
"It's been 30 years since my brother's murder, and I still don't feel that I could ever forgive the killer, and I certainly haven't forgotten what happened to our family because of it," said one.
"If we were ever lucky enough to meet the killer, I would still shake with anger and loss staring directly into his/her eyes. I do know that having that closure, I would feel better, but I don't think that I would ever forgive."
And the release this week in Lockerbie was particularly disturbing to some.
"I admire the Scottish judge's sense of compassion, but it should have been for the 270 innocents slaughtered," said another. "Would you have let Rudolf Hess go because he was getting old and had spent 40-odd years in Spandau prison [in Berlin]?"
"I am pretty outraged," said another. "He killed nearly 300 people and he's only served eight years in prison. It hardly seems just for him to go home to live out his last days with friends and family while he robbed so many people of the same."
"I do think that we should forgive people for their actions in many cases, but I don't know how I would feel if that were my husband, son or daughter on that plane," said another commenter.
But Rosamond Rhodes, professor of bioethics at Mount Sinai School of Medicine in New York City, confessed, "I am peculiar. I don't get it with forgiveness."